Frequency control of a single-frequency fiber laser by cooperatively induced spatial-hole burning

A simple frequency control method of a single-frequency fiber laser is proposed and demonstrated. The mechanism of the frequency control arises from cooperatively induced spatial-hole burning (SHB) in a saturable absorber in the laser cavity. The SHB is formed by an external frequency-stabilized light source and the lasing light. Consequently, the lasing frequency can be tuned to the external light frequency. Moreover, narrow-linewidth operation is possible even when an external-source with a broad-linewidth is employed.